This disclosure is generally directed to a dual media type printer and method that is capable of printing with both conventional print technologies that apply marking material on conventional media and with inkless and tonerless print technologies on reimageable and reusable transient media, such as photochromic paper.
Conventional printing by xerographic and inkjet print technologies is known. Inkjet printing has a well-established market and uses a relatively low-cost process, where images are formed by ejecting droplets of ink in an image-wise manner onto a substrate. Inkjet printers are widely used in home and business environments, and particularly in home environments due to the low cost of inkjet printers. Inkjet printers generally allow for producing high quality images, ranging from black-and-white text to photographic color images, on a wide range of substrates such as standard office paper, transparencies, and photographic paper.
However, despite the low printer costs, the cost of replacement inkjet cartridges can be high, and sometimes higher than the cost of the printer itself over the life of the machine. These cartridges must be replaced frequently, and thus replacement costs of the ink cartridges are a primary consumer complaint relating to inkjet printing. Reducing ink cartridge replacement costs would thus be a significant enhancement to inkjet printing users.
In addition, many paper documents are promptly discarded after being read. Although paper is relatively inexpensive, the quantity of discarded paper documents is enormous and the disposal of these discarded paper documents raises significant cost and environmental issues. Accordingly, there is a continuing desire to provide a new medium that can display a desired image temporarily, and methods for preparing and using such a medium.
To address these problems, a number of transient media approaches have been developed for transient image formation and storage. These media are designed to replace conventional paper for some applications. However, many forms of transient media provide less than desirable results as a paper substitute. For example, alternative technologies with transient images include liquid crystal displays, electrophoretics, and gyricon image media. While these technologies do provide the desired reimageability, they do not provide a document that has the appearance, feel or portability of traditional paper, nor the low cost that allows users to feel comfortable occasionally losing sheets. More recently, transient document media have been developed having a more paper-like form, such as photochromic paper. Photochromic media is typically marked upon using ultraviolet (UV) light and typically erased with light and/or heat. The media or paper is designed so that it may be reused with different images rendered thereon, in order to replace paper printing in some applications.
Imaging techniques employing photochromic materials, that is materials which undergo reversible or irreversible photoinduced color changes, are known. For example, U.S. Pat. No. 3,961,948 discloses an imaging method based upon visible light induced changes in a photochromic imaging layer containing a dispersion of at least one photochromic material in an organic film forming binder. Other known photochromic materials can be found in U.S. Patent Application Publication No. US2005/0244742 filed Apr. 29, 2004; U.S. Patent Application Publication No. US200510244743 filed Apr. 29, 2004; U.S. Patent Application Publication No. US2005/0244744 filed Apr. 29, 2004; U.S. patent application Ser. No. 12/206,136 filed Sep. 8, 2008 and U.S. patent application Ser. No. 12/400,276 filed concurrently herewith, the disclosures of which are incorporated by reference in their entireties.
These and other photochromic (or reimageable) papers are desirable because they can provide imaging media that can be reused many times, to transiently display images and text. For example, applications for photochromic based media include reimageable documents such as, for example, paper versions of electronic documents. Reimageable documents allow information to be kept for as long as the user wants, then the information can be erased and the media can be re-imaged using an imaging system with different information.
Transient document printers have been described, for example, in U.S. Patent Application Publication No. US2008/0310869 to Iftime et al. and U.S. Patent Application Publication No. US2008/0191136 to Shrader et al., the disclosures of which are incorporated by reference in their entireties.
However, transient media systems often suffer from problems not faced by conventional print media, such as paper printed by a laser printer or ink jet printer. Transient media, particularly photochromic paper, has only limited document image life before the image fades or self-erases, typically on the order of several hours to a few days depending on conditions and media used, and may have a degraded appearance when exposed to elevated light or heat conditions once printed. Thus, transient document printers and photochromic papers cannot fully replace conventional printing where archival quality is sometimes needed. Moreover, transient media systems cannot operate with standard papers or standard print technologies. That is, a transient printer will not print on conventional paper because conventional paper does not have the photochromic materials required for image formation. Likewise, a conventional printer cannot print on photochromic paper, without ruining the reusability of the transient media by depositing permanent marking material on the media. Thus, when a consumer wants to use both types of media sheets, a separate stand-alone system for each type of print technology has been used.